Diversity Analysis of Rotifers from Temporary Spring Pools of Jallo Park, Lahore, Pakistan

Temporary pools are relatively small water bodies with limited resources and are seasonally available. These freshwater bodies are rich source of microbial and planktonic lifeObjective: This survey was conducted to find out the presence of rotifers in temporary pools formed inJallo Park established in 1978 and explore their density and diversityMethods: Sample collection was done from ten pools with the help of a planktonic mesh. The counting was performed with a Sedgwick- Rafter chamber. Diversity indices like Shannon Weaver index etc. Were applied Results: In present study 27 rotifer species belonging to 14 genera were identified. The highest diversity and density was shown by Brachionus and Lecane. There was even distribution in each pool. Results of ANOVA showed statistically significant difference in population density and diversityConclusions: This study has presented a guideline to find out rotifer diversity which could be present in any water reservoir like temporary pool.

Effect of Saline And/Or Sodic Waters on Growth, Ionic Concentration and Biochemical Changes in Sunflower Helianthus Annuus L.

Scarcity of good quality irrigation water is one of the crop limiting factors in Pakistan. Information on the relative tolerance of different crop genotypes is necessary for the successful management of salt affected land and water. To investigate the effect of saline and/or sodic waters on growth, ionic concentration and biochemical changes in sunflower, a series of solution culture and pot experiments were conducted. Initially, 10 sunflower genotypes were grown for 30 days in hydroponics using five levels of saline and/or sodic water;T 1 (control), T 2 (EC 10.0 dS m -1 ), T 3 (SAR 20.0 mmol L -1 ) 1/2 , T 4 (RSC 5.4 mmol c L -1 ), T 5 (EC 10.0 dS m -1 ) + (SAR 20.0 mmol L -1 ) 1/2 + (RSC 5.4 mmol c L -1 ). On the basis of biomass accumulation and K + : Na + , ratio SF-187 and Hysun-33 emerged as salt tolerant and salt sensitive genotypes respectively. Subsequently, growth and yield response of these genotypes was evaluated in soil culture under various saline and/or sodic water treatments. Although, growth and yield of both genotypes decreased under saline and/or sodic water treatments but SF-187 produced a significantly (P ≤0.05) higher yield as compared to Hysun-33. In the next pot studies, Ca and Si were used @100 mg kg -1 soil to investigate their mitigating effect using same levels of saline and/or sodic water as above. Results revealed that calcium application partially offset the deleterious effects of saline and/or sodic waters and improved yield under RSC-water. However, Si significantly improved growth and yield of sunflower under saline and/or sodic water irrigation. The beneficial effects of Si were more pronounced in salt sensitive genotypes than in salt tolerant genotypes. Same sunflower genotypes when grown in solution culture, salinized with 100 mM NaCl revealed that 1 mM Si significantly enhanced activities of antioxidant enzymes as compared to 5 mM Ca. Finally, both sunflower genotypes were grown in pot culture and irrigated with saline sodic water. The results confirmed that Si alleviated salt stress and enhanced plant growth by stimulating activities of antioxidant enzymes and lowering lipid peroxidation in sunflower. Major mechanisms of Si mediated salt tolerance in sunflower include the maintenance of higher K + /Na + ratio, reduced membrane lipid peroxidation and enhanced antioxidative mechanism. Key words: sunflower, saline and/or sodic water, antioxidant enzymes, calcium, silicon